MAPREDUCE-5231. Bring back a constructor in mapred's DBInputFormat.DBRecordReader for binary compatibility with 1.x mapred APIs. Contributed by Zhijie Shen.
svn merge --ignore-ancestry -c 1488436 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1488437 13f79535-47bb-0310-9956-ffa450edef68